1. Field of the Invention
The present invention relates to a method and an apparatus for controlling the winding of an elongated element onto a collection reel with the interposition of a service fabric.
2. Description of the Related Art
The elongated element of the present invention, in particular, is an element made of elastomeric material obtained through a conventional drawing process. Such elongated element is, for example, adapted to be used in a process for the manufacturing of a tyre for vehicle wheels, in particular for making the sidewalls and/or the tread band and/or other tyre components made of elastomeric material.
Once drawn and prior to be used in the building of the tyre, the elongated element is wound on a specific collection reel. Such winding typically takes place in line with the drawing process.
As known, due to the stickiness imparted to the elongated element by the elastomeric material which it consists of, the winding of the elongated element onto the collection reel requires the simultaneous winding of a service fabric onto the collection reel. Such service fabric is interposed between the overlapped coils of the elongated element right in order to prevent the reciprocal sticking of such coils.
The service fabric is taken from a storage coil and is intended to be removed from the elongated element prior to the final use of the latter. The winding of the elongated element onto the collection reel takes place at the same time as that of the service fabric.
Throughout the present description, unless otherwise indicated, and in the subsequent claims, “elongated element” is used to indicate an element of elastomeric material having a main extension along a longitudinal direction thereof. Such elongated element preferably consists of elastomeric material only but it may also comprise textile or metal reinforcing cords incorporated in a matrix of elastomeric material.
Throughout the present description and in the subsequent claims, the definitions “upstream” and “downstream” are referred, unless otherwise indicated, to the feeding direction of the elongated element towards the collection reel.
Throughout the present description and in the subsequent claims, the expression “initial winding diameter” of the collection reel is used to indicate the outer diameter of the collection reel prior to the winding of the elongated element. Such diameter corresponds to the outer diameter of the reel core increased by the thickness of the layers of service fabric that are wound onto the collection reel before winding of the elongated element begins. Such thickness corresponds to the thickness of the service fabric when the initial winding of the service fabric onto the collection reel does not provide for the making of overlapped coils of service fabric, or to the thickness of the service fabric multiplied by the number of overlapped coils when the initial winding of the service fabric onto the collection reel provides for the making of overlapped coils of service fabric.
The expression “actual winding diameter” of the collection reel, on the other hand, is used to indicate the outer diameter of the collection reel at the instant in which it is detected. Such diameter corresponds to the outer diameter of the core of the collection reel increased by the thickness of the overlapped coils of elongated element and service fabric provided onto the collection reel when detection is carried out.
Consistently, “actual unwinding diameter” of the storage reel is used to indicate the outer diameter of the reel from which the service fabric is withdrawn at the moment in which it is detected. Such diameter corresponds to the outer diameter of the core of such reel increased by the thickness of the coils of service fabric provided onto such reel when detection is carried out.
GB 882,503 describes an apparatus for the simultaneous winding of an elongated element and of a service fabric onto a collection reel. The elongated element comprises reinforcing cords incorporated into a matrix of elastomeric material. Such element is used for making the carcass plies of a tyre. The apparatus comprises a feeding device of the elongated element towards the collection reel and a feeding device of the service fabric towards said collection reel. Rotation of the collection reel causes simultaneous winding of the elongated element and of the service fabric onto the collection reel. The service fabric, in particular, interposes between the overlapped coils of the elongated element.